We are continuing studies of the estrogen binding protein from Candida albicans to establish the in vivo function of this redox enzyme. As one approach we are studying the properties of mutants of active site residues to identify those with altered catalytic and/or ligand binding properties that may be useful in trapping in vivo substrates. The Computer Graphics Laboratory is critical in helping us to visualize and generate a homology model of the enzyme based on the structure of a highly homologous enzyme from Saccharomyces cerevisiae in order to generate the mutants of interest. In addition, we are using the graphics to try to interpret observed differences in the behavior of the mutant and wild type enzymes, e.g., pH dependent behavior, in the context of residues near the active site.